Methods, capsule and apparatuses for the production of foamed drinks

ABSTRACT

The invention provides a method for the preparation of a foamed drink comprising the steps of: providing a capsule containing a foamable ingredient; providing a receptacle positioned to collect fluid escaping from the capsule; injecting liquid into the capsule to mix with the foamable ingredient; allowing the foamable ingredient mixed with the liquid to escape from the capsule into the receptacle; followed by injecting further liquid into the receptacle in a jet having a diameter of from about 0.5 to about 2 mm to produce foamed liquid in the receptacle. The invention also provides capsules, apparatus and systems specifically adapted for use in the method. Preferably, the food ingredient is a milk powder, and the method produces a hot foamed beverage such as a cappuccino coffee.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a national stage application of PCT/GB02/01945 filedApr. 26, 2002 claiming priority to GB 0110420.7 and GB 0110421.5 filedApr. 27, 2001 and GB 0122514.3 and GB 0122515.0 filed Sep. 18, 2001.

TECHNICAL FIELD

The present invention relates to methods and apparatus for theproduction of foamed drinks, and in particular for the production offoamed multicomponent beverages such as cappuccino coffee and frothy hotchocolate.

BACKGROUND OF THE INVENTION

Multicomponent beverages are beverages that are formed by mixing twoseparately prepared liquid beverage components (other than water). Otherexamples of multicomponent beverages are for example “chocaccino” madeby mixing a hot chocolate with a coffee.

It is known to form edible foams from fresh milk, for example in milkshakes. It is also known to serve coffee and other hot beverages with alayer of hot milk foam over the liquid beverage. The hot milk foam istraditionally made by injecting steam under pressure through a hollowsteam wand into cold fresh milk to heat and foam the milk. The milk foamis then poured onto liquid coffee to form the beverage, for examplecappuccino or latte.

The milk foaming is normally carried out separately from the coffeebrewing, because the essential oils present in coffee have a deleteriouseffect on foaming.

The traditional method of forming hot milk foam for cappuccino or lattedoes not lend itself to use in beverage vending installations. This isin part because fresh or liquid milk is difficult to handle in suchinstallations. Furthermore, most vending installations are not equippedto supply steam under pressure. In addition, the use of a steam wandimmersed in the liquid milk could present contamination problems.

It is known to provide a powdered beverage whitener containingencapsulated nitrogen gas that produces a foam when it is dispersed incoffee. However, the foam does not have the same bulk and stiffness(spoonability) as a conventional cappuccino foam.

It is also known to produce a foam in a vending machine by depositing apowdered milk into a cup, followed by jetting hot water into the cup todissolve the powdered milk and foam the milk by the action of high shearbetween the water jet and the milk. This suffers from the reducedconsumer acceptability and mess associated with depositing a powderedmilk into the cup. Furthermore, the milk powder may not dissolvecompletely. In order to achieve more complete dissolution of the powderit is necessary to move the jet relative to the cup by means of an X-Ytable or similar equipment, thereby increasing the cost of theapparatus.

U.S. Pat. No. 2,977,231 describes pressurised packages containing liquidconcentrates, especially for the production of milkshakes. The packageshave a discharge orifice of diameter about 1.3 to 2.4 mm (0.05 inch to0.09 inch) and are pressurized to about 500 kPa (75 pounds). Theresulting narrow, high speed jets achieve effective mixing and foamingthrough shear forces when injected into water.

U.S. Pat. No. 3,622,354 describes packages similar to those of U.S. Pat.No. 2,997,231, but with the viscosity of the liquid concentrate in thepackage controlled so as to enable satisfactory mixing and foaming to beachieved with a nozzle diameter of about 3 mm. This enables the packageto be dispensed more quickly.

EP-A-0885154 describes a dispensing device for the preparation of afoamy beverage. The device contains a milk concentrate and ispressurised to 900-1000 kPa (9-10 bar) with an orifice diameter of atmost 1 mm. The resulting very high speed jet of the concentrate giveseffective mixing and foaming of the concentrate when it is injected intoa liquid beverage.

WO01/58786 describes a rigid molded cartridge for forming foamedbeverages, wherein the flow path of the beverage inside the cartridgeincludes a jet-forming orifice, and a surface against which the beveragejet impacts. An air inlet is provided in the cartridge, and air is drawnin through the inlet and turbulently mixed with the beverage jet insidethe cartridge to produce a foam.

BRIEF SUMMARY OF THE INVENTION

In a first aspect, the present invention provides a method for thepreparation of a foamed drink comprising the steps of: providing acapsule containing a foamable ingredient; providing a receptaclepositioned to collect fluid escaping from the capsule; injecting liquidinto the capsule to mix with the foamable ingredient; allowing thefoamable ingredient mixed with the liquid to escape from the capsuleinto the receptacle; followed by injecting further liquid into thereceptacle in a jet having a diameter of from about 0.5 to about 2 mm toproduce foamed liquid in the receptacle.

In a second aspect, the present invention provides a method of preparingfoamed drink comprising the steps of: providing a capsule for thepreparation of an edible foam, said capsule comprising side wallsdefining an interior region containing a foamable ingredient, an inletfor injecting a liquid into the said region, and an outlet for allowingliquid to escape from the said region, wherein at least one of the saidinlet and outlet comprises a constriction for providing a liquid jethaving a diameter of from about 0.5 to about 2 mm; injecting an aqueousliquid under pressure into the inlet; allowing the foamable foodingredient to mix with the aqueous liquid in the capsule; followed byallowing the aqueous liquid to escape through the outlet of the capsuleand into a receptacle as a high velocity jet.

The first and second aspects of the invention are linked by the specialtechnical feature that the initial mixing of the foamable ingredient andthe aqueous liquid takes place inside the capsule, thereby ensuring thatthe foamable ingredient is well dispersed and that the mess associatedwith the use of in-cup powders is avoided.

The foamable ingredient is any food-acceptable substance that will forma foam on high shear mixing with water. The foamable ingredient isusually at least partially dehydrated for ease of handling and maximumstorage stability. Preferably, the water content of the foamableingredient is less than 50% by weight, more preferably less than 25% byweight, and most preferably the foamable ingredient is a particulatesolid. Typically the foamable ingredient comprises a partially orcompletely dehydrated dairy or non-dairy beverage whitener such as milk.Preferably, the foamable ingredient consists essentially of a foamabledairy or non-dairy milk concentrate, for example a granulated dried milkor a spray dried milk powder, optionally fat reduced. In certainembodiments the ingredient comprises an instantised milk granulate.Various milk powders are suitable, and the fat content and othercharacteristics of the milk powder can be optimized for each case. Themilk powder may form part of a hot chocolate drink or other beverage.

The dry weight of the foamable ingredient may be from about 1 to about50 g, preferably from about 5 to about 15 g. In other words, the amountof the ingredient in each capsule is preferably sufficient for oneportion of a foamed product, e.g. one cup of a foamy beverage.

The capsule is normally disposable after one use. The capsule maycomprise at least one side formed from a substantially rigid sheetmaterial. For example, capsules having substantially cylindrical ortruncated conical shapes are envisaged. More typically the capsulecomprises a body formed at least in part from flexible film material,for example a tubular sachet formed on a form-fill-seal machine, or abody formed by bonding together front and back sheets of film materialaround the edges thereof to define a sachet. The capsule will normallybe substantially air and moisture impermeable before use in order topreserve the food ingredient in a shelf stable condition. Preferably,the package is substantially shelf stable. That is to say, it may bestored at ambient temperature and atmospheric conditions for a period ofat least 3 months, preferably at least one year, without significantdeterioration of the contents.

In certain embodiments the internal volume of the capsule is from about25 to about 100 cm³. The internal volume refers to the maximum volume ofthe capsule when any flexible parts are fully distended but notstretched. This internal volume is typically at least twice the volumeof the foamable ingredient, in order to allow space for turbulent flowand mixing of the aqueous liquid with the ingredient in the capsule.

The capsule may be provided with an inlet nozzle, for example asdescribed in EP-A-0179641 or WO-A-9905036, the entire contents of whichare incorporated herein by reference. In certain embodiments the methodmay comprise injecting liquid into two or more inlets in the capsule inorder to improve mixing with the foamable ingredient. The two or moreinlets may be connected through a manifold to a single liquid inletduct. At least one of the inlets may be angled to assist turbulentmixing and washing out of the capsule.

The method according to the invention initially operates by enabling,first, turbulent mixing of the liquid and the foamable ingredient in thecapsule, followed by deposition of the resulting mixture into thereceptacle and jetting liquid into the mixture in the receptacle toprovide foaming. The use of a capsule removes earlier problems withdirect deposition of milk solids into a receptacle and provides a betterquality foam in larger quantities.

In certain embodiments the outlet of the capsule is initially sealed byfreshness barrier. The term “freshness barrier” refers to a barrier thatis substantially impermeable to air or moisture so as to preserve thefreshness of the foamable ingredient by preventing ingress of air ormoisture through the liquid guide before brewing commences. Thefreshness barrier may be released by an external mechanical force orthermal field applied during brewing. The freshness barrier ispreferably releasable by the action of pressure and/or hot water frominside the capsule during brewing. For example, the freshness barriermay comprise a layer of a sealant that is released by the action of heatand/or moisture, such as an adhesive as described in EP-A-0179641 orWO99/05036.

For example, in certain embodiments the capsule comprises two flexiblesheets bonded together along a seam situated opposite the inlet, saidbonding being releasable by the action of heat or pressure inside thecapsule, whereby the two sheets peel apart under said action to providesaid opening.

Where the outlet is sealed by a freshness barrier as hereinbeforedescribed, the injection of liquid into the capsule initially causesmixing with the foamable food ingredient. The freshness barrier is thenreleased to form said opening, thereby releasing the food ingredientinto the receptacle.

Preferably, the aqueous liquid consists essentially of water, optionallymixed with steam. In certain embodiments the liquid is injected into thecapsule at a pressure of from about 30 kPa (0.3 bar) to about 200 kPa (2bar). These pressures are suitable for use in vending equipment withoutspecial measures.

In certain embodiments the liquid is injected in a two stages: a first,relatively low pressure stage to achieve mixing with the foamableingredient inside the capsule, followed by a second, high pressure stageto generate foam. The amount of liquid injected into the capsulecontaining the foamable material in the first stage is typically fromabout 25 ml to about 100 ml. The total amount of liquid injected in thefirst and second stages is typically about 100 ml to about 400 ml,corresponding to about a single cup of beverage.

The liquid may be injected into the foam forming jet by a peristaltic orpiston pump, preferably at an average rate of from about 250 to about2000 ml/min and more preferably from about 500 to 1500 ml/min. Theliquid may be injected in intermittent or pulsed fashion to optimize theamount of foam or the organoleptic properties of the product.

For a hot foamed beverage the temperature of the liquid is typicallyfrom about 75 to about 100 degrees C.

The step of injecting liquid into the capsule containing the foamablematerial is followed by the step of injecting a jet of liquid into thereceptacle containing the liquid/foamable ingredient mixture. The highvelocity and narrow diameter of the liquid jet provide strong shearforces that give rise to the formation of a thick foam.

The jet is normally formed by pumping liquid into a narrow-borejet-forming nozzle. The jet-forming nozzle may form part of the inlet orthe outlet of the sachet containing the foam forming ingredient. Inother embodiments, the nozzle may be provided on the beverage makingapparatus quite separately from the capsule. In yet other embodiments,the nozzle may be demountably inserted into the place of the capsulefollowing ejection of the capsule from the beverage making apparatus,and then supplied with pressurized liquid through the same injectionmeans as the capsule. The internal cross-section of the jet-formingnozzle may be a regular shape, and it may be substantially cylindrical.The simple cylindrical nozzles are especially suitable for theembodiments in which the nozzle is a disposable nozzle forming part ofthe capsule containing the foamable material, since scale formation isnot an issue for disposable nozzles.

Preferably, a circular water jet is produced having a diameter of fromabout 0.5 to about 2 mm, preferably from about 0.7 to about 1.5 mm.Since water is substantially incompressible and not significantlyviscoelastic, it follows that the effective internal cross sectionalarea of the jet-forming region of the nozzle is generally from about 0.2to about 3 mm², preferably from about 0.4 to about 2 mm², for exampleabout 1 mm².

If the narrow bore, jet forming region of the jet forming nozzle is tooshort, then the inlet tends to form a spray rather than a jet. If thenarrow bore is too long, then the pressure drop across the nozzle may betoo high. Accordingly, the narrow bore region may extend for a distanceof from about 1 to about 5 mm, for example about 2 to about 4 mm alongthe direction of liquid flow. Alternatively, the bore of the jet nozzlemay be tapered, as follows.

It has been found that certain jet forming nozzle geometries areespecially useful for the methods of the present invention. Accordingly,in a further aspect, the present invention provides a beverage makingapparatus, wherein the apparatus comprises a liquid injection nozzlehaving an inlet and an outlet and a bore extending between the inlet andthe outlet, wherein the cross-sectional area of the outlet is from about0.2 to about 5 mm², and wherein the bore is tapered between the inlet tothe outlet.

The small cross-section of the outlet results in a narrow, high-velocityjet of liquid issuing from the outlet. This jet produces a foam byhigh-shear mixing of air and liquid when it hits the surface of a liquidin a receptacle. The nozzle according to this aspect of the inventionavoids the problems of blockage and scale formation in the nozzle byproviding a nozzle with a tapered bore. In particular, the nozzle isnormally tapered in the vicinity of the outlet. Preferably, the bore issubstantially continuously tapered between the inlet of the nozzle andthe outlet of the nozzle.

As noted hereinbefore, the internal cross sectional area of thejet-forming outlet is generally from about 0.2 to about 3 mm²,preferably from about 0.4 to about 2 mm², for example about 1 mm². Sincewater is substantially incompressible and not significantlyviscoelastic, it follows that a circular water jet is produced having adiameter of from about 0.5 to about 2 mm, preferably from about 0.7 toabout 1.5 mm.

The problems of scale deposition and blockage are further reduced bymaking the inner surfaces of the bore substantially smooth. That is tosay, the inner surfaces of the bore preferably do not have steps orfeatures thereon of height greater than 10 micrometers, and morepreferably the inner surfaces of the bore do not have steps or featuresthereon of height greater than 1 micrometer. The surface roughness ofthe bore expressed as the root mean square deviation of the surface fromthe mean is preferably less than 5 micrometers, more preferably lessthan 1 micrometer. Preferably the RA number as determined by BS1134-1961 or ASA B46.1-1962 is not worse than 1.6 micrometers,preferably in the range 0.1 to 0.4 micrometers.

The cross-section of the bore preferably does not include any anglesthat could nucleate scale deposition. Preferably, the cross-section ofthe bore is substantially circular.

The angle of taper of the nozzle bore is preferably small, so as toreduce turbulence of the liquid in the bore and that a jet, rather thana spray, emerges from the outlet. The taper angle may vary somewhatalong the length of the bore. Preferably, the angle of taper of the boreis in the range of from about 0° to about 10°, and more preferably it isfrom about 0.5° to about 5°, at least in the vicinity of the outlet.

Preferably, the length of the bore is in the range of from about 1 cm toabout 10 cm, more preferably from about 2 cm to about 6 cm. The nozzleis preferably formed in one piece by injection molding of athermoplastic. Preferably, the nozzle is demountably fitted to thebeverage making apparatus to permit replacement or cleaning of thenozzle. The nozzle may also be demountable so that it can be insertedand/or removed from the apparatus in a prompted multi-step brewingmethod as described further below.

Typically, the jet velocity of the liquid jet is from about 3 to about50 m/s, preferably from about 5 to about 15 m/s. This gives sufficientshear on impact with a liquid body in the receptacle to provideeffective foaming. The temperature of the liquid is preferably fromabout 80 to about 100° C. The liquid is preferably supplied to the inletat a pressure of from about 0.4 to about 2 bar (40 to 200 kPa),preferably about 0.8 to about 1.2 bar (80 to 120 kPa) which isachievable with conventional vending equipment. The flow rate per jet ispreferably from about 4 to about 40 ml/sec, preferably from about 6 toabout 18 ml/sec. A plurality of jets may be provided to speed up therate of liquid addition and foam formation. Preferably, at least oneliquid jet is inclined at an angle to the vertical in order to achieveswirling of the liquid in the receptacle. Preferably, the total amountof liquid jetted into the receptacle is from about 30 to about 150 ml,more preferably from about 50 to about 100 ml.

The receptacle is typically a cup, for example a polystyrene cup.Typically, the bottom of the receptacle is located from 5 to 25 cm belowthe outlet of the capsule.

It is occasionally found that the methods described above produce a foamhaving undesirable large bubbles near the top. In such cases the methodpreferably further comprises the step of applying a water spray to thetop of the foam in the receptacle after the step of water injection. Thewater spray disperses the larger bubbles. Typically the water spray isapplied for 1 to 5 seconds and has a small droplet size.

The methods of the invention normally comprise the step of holding thecapsule in a beverage making apparatus before the step of injectingliquid into the capsule. Preferably, the methods further comprise thestep of mechanical ejection of the capsule from the holder after thestep of injecting liquid into the capsule. For example, the beveragemaking apparatus may comprise a waste bin into which the capsule isautomatically and mechanically discarded.

The present invention is especially well suited for preparing foamedbeverages in conjunction with known brewing steps in known vendingmachines. For example preferred methods according to the inventionfurther comprise the steps of: providing a second capsule containing abeverage brewing ingredient and having an outlet for allowing fluid toescape from the capsule; injecting water into the second capsule to brewa beverage inside the capsule; and allowing the beverage to escapethrough the outlet into the receptacle.

Preferably, the step of brewing a beverage is carried out after thesteps of producing an edible foamed liquid, and the beverage escapesthrough the outlet into the edible foamed liquid in the receptacle. Thisenables drinks such as cappuccino to be made by brewing a coffee capsuleimmediately after the preparation of the foamy liquid in accordance withthe invention, thereby avoiding the deleterious effect of coffee oils onthe milk foaming.

In such methods the capsule containing a foamable ingredient and thesecond capsule containing a beverage brewing ingredient may besequentially held in, and mechanically ejected from, the same capsuleholder in the same brewing apparatus during the method.

In other embodiments, the capsule containing a foamable ingredient andthe second capsule containing a beverage brewing ingredient may besimultaneously held in the same brewing apparatus during the method.That is to say, the brewing apparatus has two clamps, or a double clamp,that can be loaded with both capsules at the start of the brewingoperation, and that then brews the capsules sequentially. The two clampsor the double clamp may, for example, hold the capsules in side-by-siderelationship, or in face to face relationship.

In yet other embodiments, a single capsule may contain the foamableingredient and the beverage brewing ingredient in separate compartmentsof the same capsule. The apparatus is then configured to brew thecompartments in the capsule sequentially.

Typically, the beverage brewing ingredient comprises ground coffee orleaf tea, preferably in an amount suitable to brew a single cup ofbeverage. For example, from about 2 g to about 12 g of ground coffee orfrom about 1 g to about 9 g of leaf tea. It will be appreciated that theconstruction of the capsule containing a beverage brewing ingredient maybe substantially similar to the construction of the capsule containing afoamable ingredient. It is a particular advantage of the presentinvention that the different capsules can be manufactured and filled onthe same equipment, and can be fed sequentially into the same capsuleholding, brewing and manipulating mechanism. The beverage brewingcapsule may additionally comprise a filter element, such as a filterpaper bonded to an interior surface thereof.

The liquid may be injected into the capsule containing the beveragebrewing ingredient in amounts, at pressures, and at temperatures similarto those described above in relation to the capsule containing thefoamable ingredient.

In other embodiments the liquid is injected into the capsule containingthe beverage brewing ingredient at pressures of from about 200 kPa toabout 2 MPa (about 2 to about 20 bar), preferably from about 200 kPa toabout 1 Mpa (about 2 to about 10 bar). These pressures areconventionally generated for brewing espresso coffee. Preferably, theliquid injected in this stage of the process consists essentially ofwater.

Preferably the total amount of liquid injected in the process accordingto the present invention is from 100 to 400 ml. Preferably the productcomprises from about 10% to about 50% of foam by volume, more preferablyfrom about 20% to about 35% foam by volume.

In a further aspect the present invention provides a beverage makingapparatus for preparing a foamed liquid by a method according to thepresent invention, comprising: a capsule holder adapted to receive acapsule containing a foamable ingredient; a first pump for supplyingliquid under pressure; a liquid injection tube connected to said firstpump for injecting liquid into the capsule; and a separate liquid jetfoaming nozzle for producing a liquid jet having a diameter of fromabout 0.5 to about 2 mm.

In certain embodiments the first pump may be used to supply liquid toboth the capsule injector and to the liquid jet nozzle. Alternatively, asecond pump is provided for supplying liquid to the liquid jet. Theliquid preferably consists essentially of water.

The dimensions and shape of the jet forming nozzle in the apparatus andsystems of the invention are preferably as described hereinbefore inconnection with the methods according to the invention.

The beverage making apparatus preferably further comprises a mechanicalejection means for ejecting capsules from the holder after waterinjection is complete.

Preferably, the apparatus further comprises a mechanism operativelyassociated with the holder to retract the injection tube or tubes whenthe holder is opened.

The liquid jet nozzle is preferably directed downwardly at a small angleto the vertical in order to swirl the beverage being foamed.

In a further aspect the present invention provides a beverage makingsystem comprising: a beverage making apparatus according to the presentinvention; a capsule containing a foamable ingredient and adapted to bereceived in the holder of the beverage making apparatus; and a secondcapsule containing a beverage brewing ingredient and also adapted to bereceived in the holder of the beverage making apparatus.

Preferably, the beverage making apparatus and beverage making systemaccording to these aspects of the invention are adapted to carry out amethod according to the present invention.

Accordingly, in a further aspect the present invention provides abeverage making system for preparing a foamed beverage by a methodaccording to the present invention, said brewing system comprising: abeverage making apparatus having a capsule holder; a capsule containinga foamable ingredient and adapted to be received in the holder of thebeverage making apparatus; and a second capsule containing a beveragebrewing ingredient and adapted to be received in the holder of thebeverage making apparatus.

In a further aspect, the present invention provides a beverage makingapparatus comprising: a holder for holding a capsule containing abeverage brewing ingredient; a source of hot liquid and an injector forinjecting the hot liquid into the capsule held in the holder to brew abeverage component in the capsule; and a control system and displayprogrammed to prompt a user to carry out the following sequential stepsin response to a command to brew a multicomponent beverage:

(a) insert a first capsule containing a first beverage brewingingredient into the holder;

(b) wait while a first beverage component is brewed from the firstcapsule;

(c) insert a second capsule containing a second beverage brewingingredient into the holder; and

(d) wait while a second beverage component is brewed from the secondcapsule.

It can be seen that the invention allows multicomponent beverages to bebrewed from equipment having a single capsule holder in astraightforward way. The holder for the capsule will typically comprisea clamp that grips the capsule while water is injected into the capsule.The clamp may comprise jaws to grip at least a portion of the capsule.The apparatus may comprise a door or tray or drawer that opens to allowinsertion of the capsule into the clamp, and that closes while liquidinjection is taking place.

The control system and display may comprise for example a liquid crystaldisplay and soft key controls. In addition to visual prompts on thedisplay screen, the prompts (a) and (c) may include mechanically openingthe capsule holder to permit insertion of a capsule.

The beverage making apparatus may further provide a prompt after prompt(d), as follows: (e) remove finished beverage from the apparatus.

In typical embodiments the prompt (a) directs the user to insert acapsule containing a foamable beverage component, for example a foamablewhitener such as a spray dried milk powder. It is preferable to foam themilk first, since the second ingredient (e.g. coffee) tends to inhibitfoaming.

Typically, the beverage making apparatus according to this aspect of theinvention has the control system and display programmed to prompt a userto select a beverage prior to said step (a). The prompt to select abeverage may be by means of one or more menu selection screens accessedby soft keys. The apparatus may also be programmed to prompt the user toprovide a payment before said step (a). The payment may be by means of acoin-freed mechanism, or a card swipe, or some other automatic debitingprocedure provided in the system.

Preferably, the control system is programmed to provide a partial refundof the payment if the brewing cycle is interrupted before the secondbeverage component is brewed from the second capsule. For example, avalue equal to the value of the second beverage component only may berefunded.

The display may show a welcome screen, such as a logo or a picture of acup of coffee, when not in use. The apparatus may also be programmed toprompt the user to place a receptacle in the apparatus before said step(a). The apparatus may comprise a cup-detect interlock, for example aninfrared detector interlock, to block or interrupt the operation of theapparatus if there is no receptacle in a beverage receiving position inthe apparatus.

In other embodiments the beverage making apparatus further provides thefollowing prompts between prompts (b) and (c):

(f) insert a liquid jet nozzle into the holder;

(g) wait while a high velocity jet of liquid is pumped through thenozzle.

Preferably, the liquid jet nozzle is dimensioned as described above toprovide a high velocity jet. These embodiments have the advantage thatexisting equipment can be modified for foamed beverage productionwithout the need to retrofit jet nozzles. Also, the removable jet nozzleinserted in step (f) can be made disposable to avoid problems of scalebuild-up in jet nozzles.

In a further aspect the present invention provides a beverage makingsystem comprising a beverage making apparatus according to theinvention, at least one first capsule containing a first beveragecomponent, and at least one second capsule containing a second beveragecomponent different from the first component. Preferably, the firstbeverage component comprises a foamable beverage ingredient and thesecond beverage component comprises coffee or tea.

The invention further provides a method of brewing a beverage,comprising the steps of: providing a beverage making system according tothe invention, instructing the system to brew a multicomponent beverage,and inserting the first and second capsules into the holder in responseto prompts provided by the system in order to brew the saidmulticomponent beverage.

Typically, the beverage brewing ingredient comprises ground coffee orleaf tea, preferably in an amount suitable to brew a single cup ofbeverage. For example, from about 2 g to about 12 g of ground coffee orfrom about 1 g to about 9 g of leaf tea. It will be appreciated that theconstruction of the capsule containing a beverage brewing ingredientwill normally be substantially similar to the construction of thecapsule containing a foamable food ingredient. It is a particularadvantage of the present invention that the capsules can be manufacturedand filled on the same equipment, and can be fed sequentially into thesame capsule holding, brewing and manipulating mechanism. The beveragebrewing capsule may additionally comprise a filter element, such as afilter paper bonded to an interior surface thereof.

The liquid may be injected into the capsule containing the beveragebrewing ingredient in amounts, at pressures, and at temperatures similarto those described above in relation to the capsule containing thefoamable ingredient.

In other embodiments the liquid is injected into the capsule containingthe beverage brewing ingredient at pressures of from about 200 kPa toabout 2 MPa (about 2 to about 20 bar), preferably from about 200 kPa toabout 1 Mpa (about 2 to about 10 bar). These pressures areconventionally generated for brewing espresso coffee. Preferably, theliquid injected in this stage of the process consists essentially ofwater.

Preferably the total amount of liquid injected in the process is from100 to 400 ml. Preferably the product comprises from about 10% to about50% of foam by volume, more preferably from about 20% to about 35% foamby volume.

In certain embodiments a first pump may be used to supply liquid to boththe capsule injector and to the liquid jet outlet. More usually a secondpump is provided for supplying liquid to the liquid jet. The liquidpreferably consists essentially of water.

The beverage making apparatus preferably further comprises a mechanicalejection means for ejecting capsules from the holder after waterinjection is complete.

Preferably, the apparatus further comprises a mechanism operativelyassociated with the holder to retract the injection tube or tubes whenthe holder is opened.

Preferably, the apparatus and systems according to the present inventioninclude a cup-detector, whereby beverage brewing is interrupted unlessthe cup-detector records the presence of a receptacle in a position inthe apparatus to receive liquid from the capsule outlets. Preferably,the cup detector includes a source of infrared radiation and a sensorfor said infrared radiation, in particular a sensor for infraredradiation reflected from a surface of the receptacle when the receptacleis correctly positioned in the apparatus. Preferably the apparatus isadapted to prompt the user to insert a cup in the event that thedetector does not detect a cup in the correct position.

The foamy beverage producing methods of the present invention requireminimal adaptation of existing beverage vending equipment, and inparticular avoid the need for high pressures or steam injection.Furthermore, they can frequently be used in conjunction with existingbeverage brewing ingredient pack formats, or with minimal adaptation ofsuch formats.

As already discussed, in certain aspects of the methods according to thepresent invention the high velocity liquid jet may be formed by an inletor outlet nozzle provided in the capsule containing the foamableingredient. Accordingly, in a further aspect, the present inventionprovides a capsule for the preparation of an edible foam comprising:side walls defining an interior region containing a foamable ingredient;an inlet for injecting a liquid into the said region; and an outlet forallowing liquid to escape from the said region, wherein at least one ofthe said inlet and outlet comprises a constriction for providing aliquid jet having a diameter of from about 0.5 to about 2 mm.

The foamable ingredient may be any food-acceptable ingredient that formsa foam on high-shear mixing with water, as hereinbefore described.

The dry weight of the foamable ingredient may typically be from about 1to about 50 g, preferably from about 2 to about 15 grams, morepreferably from about 5 to about 12 grams. In other words, the amount ofthe ingredient in each package is preferably sufficient for one portionof the foamed product, e.g. one cup of a foamy beverage.

Preferably, the package is substantially shelf stable. That is to say,it may be stored at ambient temperature and atmospheric conditions for aperiod of at least 3 months, preferably at least one year, withoutdeterioration.

The capsule is normally formed of thermoplastic material, and isdisposable after one use. The capsule may comprise at least one sidewall formed from a substantially rigid sheet material. For example,capsules having substantially cylindrical shapes are envisaged. Moretypically the capsule comprises a side wall formed from flexible filmmaterial, for example a tubular sachet formed on a form-fill-sealmachine, or a body formed by bonding together front and back sheets offilm material around the edges thereof to define a sachet. The capsulewill normally be substantially air and moisture impermeable before usein order to preserve the food ingredient in a shelf stable condition.

In certain embodiments the internal volume of the capsule is from about25 to about 100 cm³. The internal volume refers to the maximum volume ofthe capsule when fully distended. This internal volume is typically atleast twice the volume of the foamable ingredient, in order to allowspace for turbulent flow and mixing of the aqueous liquid with theingredient in the capsule.

The inlet or outlet is adapted to provide a narrow diameter liquid jetinto the interior of the capsule, and/or out of the interior of thecapsule in use. The resulting high shear mixing when the jet hits aliquid surface containing the foamable ingredient results in foamformation.

Preferably, the constriction provides a jet having a diameter of fromabout 0.7 to about 1.5 mm, more preferably about 1 mm.

In certain embodiments the capsule may comprise two or more jet-forminginlets or outlets in order to combine high shear with an increasedliquid flow rate. The two or more inlets may be connected through amanifold to a single liquid inlet duct. At least one of the inlets maybe angled to assist swirling and washing out of the capsule.

The internal cross-section of the jet-forming inlet or outlet isnormally a regular shape, and preferably it is substantially circular.Since aqueous liquids are substantially incompressible and notsignificantly viscoelastic, it follows that the internal cross sectionalarea of the jet-forming region of the inlet and/or the outlet isgenerally from about 0.2 to about 3 mm², preferably from about 0.4 toabout 2 mm², for example about 1 mm².

If the constriction (narrow bore, jet forming region) of the inlet oroutlet is too short, then the inlet or outlet tends to form a sprayrather than a jet. If the constriction is too long, then the pressuredrop across the constriction may be too high. Accordingly, theconstriction preferably extends for a distance of from about 1 to about5 mm, preferably about 2 to about 4 mm along the direction of liquidflow.

In certain embodiments the jet forming region of the inlet or outlet maycomprise a disposable nozzle. The nozzle may be formed by injectionmoulding of plastic material and may be secured in liquid-tight fashioninto a seal between front and back sheets of film material making up thecapsule, substantially as described in EP-A-0179641 or WO-A-9905036. Inthese earlier documents the bore area of the nozzle was substantiallygreater than 3 mm² in order to provide rapid flow of liquid into thesachets. The nozzle in the capsules according to the present inventionmay comprise an inlet duct of diameter about 3 mm or more forcompatibility with existing beverage brewing machines, but the exit fromthe nozzle may have a constricted cross-section to form a jet ashereinbefore described. The disposable inlet or outlet nozzle providesthe advantage that it does not get blocked by scale or contaminated byprolonged use.

In certain embodiments the capsule outlet is sealed by freshnessbarrier. The term “freshness barrier” refers to a barrier that issubstantially impermeable to air or moisture so as to preserve thefreshness of the beverage brewing ingredient by preventing ingress ofair or moisture through the liquid guide before brewing commences. Thefreshness barrier may be released by an external mechanical force orthermal field applied during brewing. The freshness barrier ispreferably releasable by the action of pressure and/or hot water frominside the sachet during brewing. For example, the freshness barrier maycomprise a layer of a sealant that is released by the action of heatand/or moisture, such as an adhesive as described in EP-A-0179641 orWO99/05036.

In certain embodiments of the invention, the constriction is provided inthe inlet. In such embodiments, the outlet is preferably locatedsubstantially opposite to the inlet. An advantage of the outlet beinglocated opposite the inlet is that the jet from the inlet can clearblockages of the outlet caused by incompletely dispersed foambleingredient.

In certain other embodiments, the jet forming constriction is providedin the outlet only. An advantage of such embodiments is that the outletnozzle can be angled to swirl the liquid in the receptacle. However,these embodiments are not preferred, since the outlet is then prone toblocking by particles of the foamable material. Preferably, the capsulecomprises either a jet-forming outlet situated opposite to a jet forminginlet, as described above, or a large outlet situated opposite to a jetforming inlet, as follows.

In the large-outlet embodiments the outlet is adapted to provide, inuse, an opening having a cross sectional area preferably greater thanabout 1 cm², whereby a jet of water issuing from the inlet can passthrough the capsule and out of the opening substantially withouttouching the side walls of the capsule. The jet then impacts the liquidin a receptacle below the capsule to cause foaming.

Preferably, the outlet is sealed by a freshness barrier as hereinbeforedescribed, so that the injection of water into the capsule initiallycauses mixing with the foamable food ingredient. The freshness barrieris then released to form said opening, whereby releasing the foodingredient into the receptacle, followed by further water injection,produces foam in the receptacle.

For example, in certain embodiments the capsule comprises two flexiblesheets bonded together along a seam situated opposite the inlet, saidbonding being releasable by the action of heat or pressure inside thecapsule, whereby the two sheets peel apart under said action to providesaid opening.

In certain embodiments the capsules used in the methods and systems ofthe present invention may comprise machine readable pack recognitionmeans on the capsule to assist use of the capsule in fully automatedvending equipment. For example, the capsules may comprise machinereadable projections or perforations or a bar code. In these embodimentsthe apparatus comprises compatible machine recognition capabilities torecognize and manipulate the capsules.

It will be appreciated that the optional and/or preferred featuresdescribed in conjunction with any one of the above aspects of theinvention may also be present, alone or in combination with any of theother optional and/or preferred features, in capsules, beverage makingapparatus or systems, nozzles or methods according to any other aspectof the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Specific embodiments of the present invention will now be describedfurther, by way of example, with reference to the accompanying drawings,in which:

FIG. 1 shows a plan view of a first capsule containing a foamableingredient for use in a first method according to the present invention;

FIG. 2 shows a longitudinal sectional view through the capsule of FIG.1;

FIG. 3 shows the capsule of FIGS. 1 and 2 after injection of liquid intothe capsule has been completed, and while further injection of a jet ofliquid into a receptacle is taking place;

FIG. 4 shows a longitudinal cross-section through a liquid injectionnozzle according to the present invention for use in the beverage makingmethod and apparatus of FIG. 3;

FIG. 5 shows a detail cross-sectional view of the inlet nozzle region ofa capsule according to the present invention for use in a second methodaccording to the invention;

FIG. 6 shows a schematic longitudinal sectional view through the capsuleof FIG. 5 in use in use to brew a foamed beverage; and

FIG. 7 shows a plan view of a further capsule according to the presentinvention for use in a further method according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1 and 2, the capsule 1 is in the form of a sachetformed from two sheets of laminated, metallized flexible plastic film2,3 bonded together around a margin 4. A lower part 5 of the margin isbonded by means of a layer of adhesive 8 that can be released by theaction of hot water inside the sachet. In a top margin of the sachet anozzle 7 is inserted between the sheets 2,3 and bonded thereto in airtight fashion. The capsule has an internal volume of approximately 50cm³ when fully distended. Thus far the construction of the package 1 issimilar to the beverage brewing sachets described in EP-A-0179641 orWO99/05036. The capsule is approximately half filled with approximately5-10 g of a foamable powdered milk 6.

The nozzle 7 is formed by injection moulding of a thermoplastic materialsuch as polypropylene. It is bonded by adhesive or melt bonding inair-tight fashion to the front and back sheets 2, 3 of the sachet. Thenozzle 7 comprises a bore region having a uniform internal diameter ofapproximately 3 mm, into which a water injection tube 15 is inserted inuse. A flange is provided at the top of the nozzle to assist mechanicalgripping and manipulation of the sachet in the brewing apparatus.Finally, a plastics laminated foil freshness barrier (not shown) issealed over the top of the nozzle. This results in a fully air tight andmoisture-tight package that is shelf stable.

With reference to FIG. 3, in use the capsule 1 is held in a beveragemaking apparatus by capsule holder 11 which grips the capsule below thenozzle flange. A water inlet tube 15 is advanced to pierce the freshnessbarrier in the nozzle 7, and hot water at about 90° C. is then injectedthrough the tube 15 into the capsule 1. A first pump P may be used tosupply liquid to both the capsule injector via inlet tube 15 and to theliquid jet nozzle 12. The hot water undergoes turbulent mixing with thepowdered milk 6 in the capsule 1 to product an aqueous dispersion of thepowdered milk. The hot water also releases the seal 8 at the bottom ofthe capsule, thereby allowing the aqueous milk dispersion to drop intothe receptacle 17. The total amount of water injected in this stage isabout 50 ml.

Once water injection into the capsule 1 is complete, the beverage makingapparatus automatically jettisons the used capsule into a wastereceptacle. Simultaneously or sequentially, a jet of water 13 is pumpedinto the liquid mixture in the receptacle 17 through jet inlet 12. Thejet diameter is about 1 mm, the jet velocity is about 5 m/s and theamount of water injected through the jet is about 60 ml. The jet ofwater causes foaming of the mixture in the receptacle 17 to produce afoamed liquid comprising a liquid layer 18 and a foam layer 19.

The jet inlet 12 comprises a nozzle 20 according to the presentinvention, as shown in more detail in FIG. 4. The nozzle 20 is formed inone piece by injection molding of a thermoplastic such as a polyacetal,polypropylene or other food-approved plastic. The length of the nozzleis about 5 cm and the wall thickness is in the range 0.2 to 1.5 mm. Thenozzle tapers from an inlet 22 having an inside diameter of about 4 mmto an outlet 24 having a diameter of about 1 mm. The bore 26 of thenozzle is circular in cross-section tapered along its whole length withan included taper angle of about 2 degrees. The low taper angle resultsin a jet, rather than a spray, of water at the outlet. The insidesurface of the bore is 26 very smooth in order to minimize limescaledeposition. The nozzle is provided with flanges 28, 29 to permitinsertion and replacement of the nozzle in the apparatus using aspring-loaded bayonet fitting or similar.

Referring now to FIGS. 5 and 6, an alternative method according to theinvention uses a sachet that is specifically adapted according to thepresent invention. The construction of the sachet is similar to thebeverage brewing sachets described in EP-A-0179641 or WO99/05036 andshown in FIGS. 1 and 2. However, the sachet differs from the earliersachets in that the inlet nozzle is adapted to form a high velocity jetas described further below.

Referring to FIG. 5, the inlet nozzle of the inventive sachet is formedby injection moulding of a thermoplastic material such as polypropylene.It is bonded by adhesive or melt bonding in air tight fashion to thefront and back sheets 30, 31 of the sachet. The nozzle comprises anarrow bore region 32 having a substantially cylindrical boreapproximately 3 mm long and 1 mm in diameter. The nozzle furthercomprises a relatively wide bore outer region 33 having an internaldiameter of approximately 3 mm, into which a water injection tube isinserted in use. A flange 34 is provided at the top of the nozzle toassist mechanical gripping and manipulation of the sachet in the brewingapparatus. Finally, a plastics laminated foil freshness barrier 35 issealed over the top of the nozzle. This results in a fully air tight andmoisture-tight package that is shelf stable.

Referring to FIG. 6, in this method according to the invention thesachet is inserted into a beverage making apparatus (not shown), inwhich it is gripped by jaws (not shown) under the flange 34. A waterinjection tube 36 attached to the apparatus is advanced until it piercesthrough the freshness barrier film 35 and forms a pressure-tight matingfit in the wide bore section 33 of the nozzle. Water at about 90° C. andat an initial pressure of about 0.2 bar (20 kPa) is injected through thenozzle and into the capsule, where it mixes with the powdered milk toform a concentrated milk dispersion. The hot water and pressure themrelease the adhesive bond in the lower margin of the capsule and theconcentrated milk dispersion drops into the receptacle 38. This initialinjection stage typically takes from 5 to 10 seconds, and the totalamount of water injected in this stage is from 50 to 60 ml.

The water injection pressure is then increased to approximately 2 bar(200 kPa), which causes the water to emerge from the narrow bore section32 of the nozzle as a high velocity jet having a diameter ofapproximately 1 mm and a velocity of approximately 15 m/sec. This highenergy jet 37 impacts the liquid 39 present in the receptacle 38 withhigh shear mixing to produce a layer of foam 40. The water jet injectionstage typically takes from 10 to 30 seconds, and the total amount ofwater injected is from 10 to 250 ml.

After the step of water injection is complete, the injection tube 36 isretracted, and the empty capsule is ejected into a waste receptacle. Awater spray (not shown) is then briefly applied to the foam 40 in thereceptacle 38 to disperse any large bubbles present at the top of thefoam layer 40 to provide a stable, spoonable milk foam layer.

Referring to FIG. 7, alternative inventive capsule 42 also comprisesfront and back sheets of metal laminated flexible plastic sheet materialbonded together around a margin 43. A nozzle 45 of similar constructionto the nozzle of the embodiment shown in FIG. 5 is inserted in topregion of the margin. An outlet nozzle 46 is inserted in a bottom region44 of the margin. The nozzle 46 provides the sole outlet from thecapsule, since the margin 44 is not releasable by the action of heat orwater inside the capsule. The nozzle 46 is molded from thermoplastics insimilar fashion to the nozzle of FIG. 5, and has a narrow bore adaptedto provide an outlet jet of diameter about 1 mm. A freshness barrierfilm is provided in the nozzle 46 that can be ruptured by pressure.

In use the package of FIG. 7 is clamped tightly in a cavity having aclam shell configuration within the beverage making apparatus. Thecavity encloses and supports the package and prevents it from burstingunder the pressure of injected water. Water is injected into nozzle 43initially at fairly low pressure as describe above in relation to theembodiments of FIG. 5. The water mixes with the powdered milk in thesachet, and the pressure inside the sachet increases until the freshnessbarrier in the outlet nozzle 46 bursts, whereupon the mixture is ejectedas a high velocity jet from the outlet nozzle 46. Water injectionthrough the inlet nozzle 43 is continued at high pressure to rinse outthe capsule, clear any blockages in the outlet nozzle 46, and continueinjection into the receptacle below the package to produce a foam aspreviously described. The remaining steps of the process are asdescribed above.

The foamed milky liquid produced by any of the above embodimentsnormally requires the addition of a beverage flavour to render it morepalatable. In an embodiment of the invention a beverage brewing capsuleis inserted into the same holder in the beverage making apparatus as thefoamable milk capsule. The beverage brewing capsule is constructed insimilar fashion to the capsule of FIG. 1, but is filled with groundcoffee and incorporates a filter element. The beverage is brewed byinjection of hot water into the nozzle of the capsule in similar fashionas for the milk-containing capsule. The brewed coffee escapes from thebottom of the capsule and drops through the foam layer into the liquidlayer in the receptacle. The spent beverage brewing sachet is thenautomatically discarded by the apparatus. A fine spray of water may beapplied briefly to the top of the foam in the cup to disperse largebubbles in the foam.

A final jet of water may be briefly injected, for example through nozzle12, to swirl the contents of the receptacle and thereby mix the brewedbeverage with the milky liquid already in the receptacle.

The method according to the present invention may be carried out ineither semi-automatic or fully-automatic fashion by beverage vendingequipment. In the semi-automatic embodiment, the process is initiated bya user selecting a foamed beverage option from the vending equipment.The system prompts the user to insert a milk powder capsule by opening adoor leading to a beverage brewing enclosure equipped with the capsuleholder. The machine then automatically grips the capsule, and injectswater into the capsule for a predetermined time to achieve the initialmixing and to deposit the water and milk powder mixture into thereceptacle. The machine then automatically injects further water intothe receptacle in a high velocity jet to achieve the desired hot foamedmilk in the receptacle. The machine also automatically discards thespent capsule, either before or after the step of jetting, depending onthe particular embodiment.

In the semi-automatic mode, the machine then prompts to the user toinsert a beverage brewing capsule, and opens the clamp of the capsuleholder. The user can select the desired beverage capsule, insert it intothe same holder in the machine, whereupon the machine automaticallyinjects water into the capsule to brew the beverage inside the capsuleand to release the barrier at the bottom of the capsule to release thebeverage into the receptacle. Finally, the machine automaticallydiscards the spent brewing beverage capsule and “finishes” the foamedbeverage by a brief water jet injection to swirl the beverage, and abrief water spray over the foam to remove any large bubbles on thesurface of the foam.

In the fully automatic embodiments, the milk powder capsules andbeverage brewing capsules are stocked inside the vending machine, andthe machine additionally selects the appropriate sachets and feeds themto the sachet holder at the appropriate times in response to the initialbeverage brewing instruction from the user.

In an alternative embodiment, the jet forming nozzle is removablyinserted into the same beverage brewing clamp in the apparatus as thefoamable milk sachet and/or the beverage brewing sachet. This embodimentrequires no modification of existing brewing equipment. In thisembodiment, the foamable milk sachet shown in FIG. 1 is initiallyinserted into the apparatus as described above, and liquid is injectedinto the capsule to deposit a mixture of milk and water into thereceptacle.

The apparatus then opens the door leading to the beverage brewingenclosure and prompts the user to insert a jet nozzle into the holder.The jet nozzle is a disposable or multi-use thermoplastic nozzle havingan internal diameter adapted to provide a high velocity jet of water ofdiameter about 1 mm, as hereinbefore described. Once the nozzle isinserted, the apparatus pumps water through the nozzle to produce a highvelocity jet into the receptacle, where it forms a milky foam by highshear mixing entraining air into the liquid. The jet diameter is about 1mm, the jet velocity is about 5 m/s and the amount of water injectedthrough the jet is about 60 ml. The system then automatically discards adisposable nozzle, or alternatively opens and prompts the user to removea multi-use nozzle.

The machine then prompts to the user to insert a beverage brewingcapsule and carries out the subsequent steps as already described.

The above embodiments have been described by way of example only. Manyother embodiments falling within the scope of the accompanying claimswill be apparent to the skilled reader.

1. A method for the preparation of a foamed drink comprising the stepsof: providing a capsule containing a foamable ingredient; providing areceptacle positioned to collect fluid escaping from the capsule;injecting liquid into the capsule to mix with the foamable ingredient;allowing the foamable ingredient mixed with the liquid to escape fromthe capsule into the receptacle; followed by injecting further liquidinto the receptacle through a nozzle separate from said capsule in a jethaving a diameter of from about 0.5 mm to about 2 mm to produce foamedliquid in the receptacle.
 2. A method according to claim 1, wherein thejet is directed at an angle to the vertical to swirl the liquid in thereceptacle.
 3. A method according to claim 1, wherein the bottom of thereceptacle is located from about 5 cm to about 25 cm below the bottom ofthe capsule outlet.
 4. A method according to claim 1, wherein the liquidis injected into the capsule at a temperature of from 80 degrees C. to100 degrees C.
 5. A method according to claim 1, wherein the jetvelocity of the liquid jet is from 5 m/s to 50 m/s.
 6. A methodaccording to claim 1, wherein the liquid consists essentially of water.7. A method according to claim 1, wherein the foamable ingredientcomprises a partially or completely dehydrated dairy or non-dairybeverage whitener.
 8. A method according to claim 7, wherein thefoamable ingredient consists essentially of a foamable milk powder.
 9. Amethod according to claim 1, wherein the dry weight of the foamableingredient in the capsule is from about 5 g to about 50 g.
 10. A methodaccording to claim 1, wherein an outlet of the capsule is sealed by afreshness barrier that can be released by the action of water, heat orpressure from inside the capsule.
 11. A method according to claim 1,wherein the liquid is injected into the capsule at a pressure of fromabout 30 kPa (0.3 bar) to about 200 kPa (2 bar).
 12. A method accordingto claim 1, further comprising the steps of: providing a second capsulecontaining a beverage brewing ingredient; injecting liquid into thesecond capsule to brew a beverage inside the capsule; and allowing thebeverage to escape from the capsule into the receptacle.
 13. A methodaccording to claim 12, wherein the said steps of injecting liquid intothe second capsule is carried out after the steps of producing an ediblefoamed liquid, and the beverage is added to the edible foamed liquid inthe receptacle.
 14. A method according to claim 12, wherein the capsulecontaining a foamable food ingredient and the second capsule containinga beverage brewing ingredient are sequentially held in, and mechanicallyejected from, the same holder during said method.
 15. A method accordingto claim 12, wherein the beverage brewing ingredient comprises groundcoffee or leaf tea.
 16. A beverage making apparatus for preparing anedible foamed liquid by a method according to claim 1, comprising: acapsule holder adapted to receive a capsule containing a foamableingredient; a first pump for supplying liquid under pressure; a liquidinjection tube connected to said first pump for injecting the liquidinto the capsule; and a jet nozzle for producing a liquid jet having adiameter of from about 0.5 mm to about 2 mm.
 17. A beverage makingapparatus according to claim 16, further comprising: a liquid injectionnozzle having an inlet and an outlet and a bore extending between theinlet and the outlet, wherein the cross-sectional area of the outlet isfrom about 0.2 mm² to about 5 mm², and wherein the bore is taperedbetween the inlet to the outlet.
 18. A beverage making apparatusaccording to claim 17, wherein the bore is substantially continuouslytapered between the inlet of the nozzle and the outlet of the nozzle.19. A beverage making apparatus according to claim 17, wherein innersurfaces of the nozzle bore are substantially smooth.
 20. A beveragemaking apparatus according to claim 17, wherein the angle of taper ofthe bore is in the range of from about 0° to about 10°.
 21. A beveragemaking apparatus according to claim 20, wherein the angle of taper ofthe bore is in the range of from about 0.5° to about 5°.
 22. A beveragemaking apparatus according to claim 17, wherein the length of the boreis in the range of from about 1 cm to about 10 cm.
 23. A beverage makingapparatus according to claim 17, wherein the cross-section of the boreis substantially circular.
 24. A beverage making apparatus according toclaim 16, wherein the nozzle is demountable from the beverage makingapparatus.
 25. A beverage making system for preparing a foamed beverageby a method according to claim 1 or 12, said system comprising: abeverage making apparatus having a capsule holder; a capsule containinga foamable ingredient and adapted to be received in the holder of thebeverage making apparatus; and a second capsule containing a beveragebrewing ingredient and adapted to be received in the holder of thebeverage making apparatus.
 26. A method of preparing a foamed drinkcomprising the steps of: providing a capsule comprising side wallsdefining an enclosed region containing a foamable ingredient, an inletfor injecting a liquid into the said region, and an outlet for allowingliquid to escape from the said region, wherein said inlet comprises aconstriction for providing a liquid jet having a diameter of from about0.5 mm to about 2 mm; injecting an aqueous liquid under pressure intothe inlet; allowing the foamable ingredient to mix with the aqueousliquid in the capsule; followed by allowing the aqueous liquid to escapethrough the outlet of the capsule and into a receptacle as a highvelocity jet.
 27. A method of preparing a foamed drink comprising thesteps of: providing a capsule comprising side walls defining an enclosedregion containing a foamable ingredient, an inlet for injecting a liquidinto the said region, and an outlet for allowing liquid to escape fromthe said region, wherein said outlet comprises a constriction forproviding a liquid jet having a diameter of from about 0.5 to about 2mm; injecting an aqueous liquid under pressure into the inlet; allowingthe foamable ingredient to mix with the aqueous liquid in the capsule;followed by allowing the aqueous liquid to escape through the outlet ofthe capsule and into a receptacle as a high velocity jet; providing asecond capsule containing a beverage brewing ingredient; injectingliquid into the second capsule to brew a beverage inside the capsule;and allowing the beverage to escape from the capsule into thereceptacle; wherein the said steps of injecting liquid into the secondcapsule is carried out after the steps of producing an edible foamedliquid, and the beverage is added to the edible foamed liquid in thereceptacle.